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Homework 1, due Thurs Sep 9, 2010

Hand in during lab, or email PDF file to Peter Honig.

  1. As described in Angel, what are the 4 major components of a 3D graphics API?
  2. As described in Angel, what are the 4 stages of the graphics pipeline?
  3. Find the eigenvalues and eigenvectors of the following matrix. Suggested tools include Matlab, Maple, or doing it by hand. {$ \left(\begin{array} .8 & -.6\\.6 & .8 \end{array}\right) $}
    Use any legal tool, including Matlab, that you wish.
  4. Consider these 3-D vectors: A=(2,1,3), B=(5,4,6), C=(7,8,9). Compute:
    1. A.BxC
    2. AxB.C
  5. (This is another a test of your linear algebra knowledge. Feel free to refer to books to find the correct formulae.)
    Suppose that we have a plane in 3-D thru the points A(3,0,2), B(2,2,0), and C(0,1,1).
    1. What is its equation, in the form ax+by+cz+d=0?
    2. Consider the line L thru the points O(0,0,0) and P(1,1,1). Where does this line intersect the plane?
  6. This is a test of whether you know enough C for this course. The following code will copy string s to array t, provided that a few erroneous lines are corrected. What are the corrections and proper initializations?
    char *s="Hello!";
    char t[6];
    char p, q;
    for (;*q++ = *p++;);
  7. If we're going to be learning complicated graphics in this course, it behooves us still to be able to do the simple things. So, this exercise is to plot the ship NCC1701 similarly to the plot shown in the right margin.

Here is a compressed file of 3,958 triangles defining the USS Enterprise. It looks like the image on the right when uncompressed with gunzip:

1.431000 0.505000 0.843000
1.572000 0.505000 0.801000
1.287000 0.505000 0.802000
1.431000 0.505000 0.843000

1.572000 0.505000 0.801000
1.595000 0.542000 0.794000
1.263000 0.542000 0.795000
1.572000 0.505000 0.801000

1.572000 0.505000 0.801000
1.263000 0.542000 0.795000
1.287000 0.505000 0.802000
1.572000 0.505000 0.801000

... and similarly for 23730 more lines

Each line of the file represents one vertex in the form: (x, y, z). Four lines make one triangle; the first vertex is repeated. Two blank lines separate each triangle.

You may want to cut off a piece of the file for testing. This is how to do that in Linux.

head -1000 /tmp/ncc > /tmp/piece

Plot the data. I used gnuplot; you may use whatever you like. It's ok to render it as polygons if you wish. You don't need to delete hidden lines, i.e., don't over-engineer the plot.

If you need to transform the datafile for your chosen plotting program, consider a powerful editor like emacs or a string processing tool like awk or sed. These particular tools might not be as readily available in some major commercial platforms. However, surely such platforms have other equally powerful tools, don't they?